Are all hairy crabs bad for coral?

[sugartooth]

Hello,
I got some coral shipped and noticed a few "smooth" crabs that made it along some pocillipora. However, in one of my acros (tri colored with fluorescent polyps) there is this really small, more squat than flat and wide, hairy, brown crab with bright eyes that match the polyp color.
The hairiness of the crab seems to be more prickly than fine filament like.
I saw on another post that all hairy crabs are bad. I want to confirm this before taking it out since I don't want to disrupt the situation if the crab is supposed to be there. As of yet, it does not look like there is damage to the coral, and he has not left the coral.
Any experiences? Your advice is greatly appreciated.
Thanks!

 

[marine_freak]

Hairy blue eyed crabs are bad you better get em as a matter of fact all hairy leg crabs are bad news.... smooth leg and body crabs are ok.......

 

[Jocko]

Interesting... assuming crabs are good just because they are smooth... good luck with that.

 

[RichConley]

<a href=showthread.php?s=&postid=7388524#post7388524 target=_blank>Originally posted</a> by marine_freak
Hairy blue eyed crabs are bad you better get em as a matter of fact all hairy leg crabs are bad news.... smooth leg and body crabs are ok.......

I hear this a lot, and I've never seen any evidence to back it up. While not an acro crab, my emeralds have hairy legs, and they've never bothered anything.

 

[Rays]

I am so sick and tired of seeing hairy crabs kill them, I've had three or four of them in my tank for over three years, and Never had one incident with my SPS ever! It's like see a snake, kill it See a bug kill it this is all BS. I'm sure there may be some harmful crabs, but you can't prove by me they are all harmful!

 

[jer77]

What exactly will the hairy crabs do that the smooth crabs won't do to acros?

 

[coralfarmer84]

I had a hairy type crab living on my green slimer. he would hide during the day but at night come out and eat flesh off the colony. i noticed several eaten polyps in small clusters on the colony. it was getting worse and worse, i removed him and now the colony is healing and looks much better. I'd just keep an eye out, if things start to look bad, pull him, if not dont' worry i guess. Its not like one lil crab is gonna kill all your colonies overnight, you'll be able to see his destruction. Good luck

 

[isseym328]

crab bad for acros good for eating.

 

[Harlequinreef]

hairy blue eye crabs (family xanthidae) that live in acro colonies usually feed on acro colonies. They are parasitic rather than commensal. Crabs in general are omnivores. If there is edible flesh availible, almost all crabs will consume this rather than plant matter. Symbiotic acropora crabs (family trapeziidae) also feed off of their host, mainly mucus, but also help defend the coral from predators. Try squirting mysis shrimp onto an acro colony and see how rapidly a trapeziid crab consumes it. Mithrax crabs (emerald crabs) are certainly omnivores. If very little algae is present which should and is often the case in an sps dominated tank, the crab must resort to predation. Whether the damage is signifcant or not, it is still damage. I have also observed on several occasions emarld crabs roosting in acro colonies causing irritation. In large tanks with large colonies, this may not be a major cause for concern.
-austin

 

[clkwrk]

IME every single weird hairy crab has eaten some kind of coral . Whether its the blue eyed sps eating crabs to the lil white fuzzy soft coral eating crabs .

 

[marine_freak]

I got one in my echinata colony he is small and fast ( Blue eyed hairy) he will be in my sump or dead by dawn........ You guys can keep em if you like, I like my acros far too much to take that chance

 

[sugartooth]

My hairy crab

My hairy crab

Thanks everyone for your input. My crab is more prickly than hairy, and he has fluorescent looking eyes (very similar to the fluorescent tips of the acro), not blue. He looks just like the acro but textured, and that's how I noticed him.
I have seen him picking at the coral, but I can't tell if there has been any damage yet. Also, he has not left the coral at all.

I have found this link that talks a little bit about the myths of hairy crabs.

http://www.reefkeeping.com/issues/2003-12/eb/index.php

I guess the best thing to do is wait to see if there is damage. I would hate to just yank him based on assumption.

Let me know please if there is any more info!
Thanks!